Hardness-testing machine



Aug. 17,1926, 1,596,003 D. C. DAVIS HARD-NESS TESTING MAcHlNE Filed July e 1925 2 Sheena-,sheep 2 Y @@@gmi Afrox/Me ed Aug. 17, 19g@ narran eras@ DONALD C. DAVIS, OF XTILLIAIVSVLLE, NEW' YORK.

HARDNESS-TESTING- llAO-IINE.

Application filed July 6, 1925. Serial No. 41,664.

This invention relates to improlven'ients '1n machines torv testing the hardness et materials by the Brinell method, in which a. hardened steel ball is pressed against the sample or piece of material to be tested, the l'lardness ot which is determined lrom the measurement ot the indentation made by the ball in the sample under a predetermined pressure. y

The objects of the present invention are to provide a machine ot the character stated which 1s designed and especially' adapted to be Qperated by power so that tests may be made rapidly and expeditiously; also to construct a machine of this kind having an adjustable reciprocating' work supporting; element and a rotary element lor causing` the actuation ot the same, and also to provide a lost motion connection between said elements so that the reciprocatory movement ot said work supportinp;lelen'ient will take place during a relatively short portion of the period of revolution ot said rotary element so as to allow ample time for the insertion and removal of the samples or work pieces; also to provide improved, simplified' and quickly actuated adjusting, means tor p'crinittiiue` the' machine to be adapted to diltereut thicknesses of samples; and also to provide novel take up and stop means adapted to permit the return ot the reciprocating work supportingelement to its initial lower position at the ond oi' each test, said means beine; such as to prevent changes in the reciprocating: or actuating1 means due to wear or otherwise lOther objects are to provide nlachi'nes of this character with an improved measuring clement and measurement indicating means, and also to improve such machines in the other respects hereinafter specified Y and claimed.

ln the drawings l is a tirent elevation, partly in section, of a hardness testinemachine embodyinni my invention.

Fig'. 2 is a plan view thereof. Y

F 3 is a fragmentary. vertical section, on an lenlarged scale. on line 3%3, Fig. l, or" the lost motion connection between the reciprocatory worl': support and the rotary actuating' element therefor.

4 is a transverse, sectional elevation ci' the machine on line lut l.

Fig. 5 is an enlarged, fragmentary sec` tional elevation thereof, showing the parte Fig. 8 is a horizontal section,` on line 8 8,

Fig. 7, of the measurement indicating means.

Briefly stated, the .machine comprises a stationary trame, a vertically reciprocableA work support or platen arranged thereon, a drive .shaft journalled in theY trame, and means actuated by said shaft and adapted to reciprocate the work support or platen. Screw rods or members extend upwardly from the frame and adjustably support a measuring` element embodying a plunger which carries the testing` ball or member. a spring which yieldingly opposes upward movements ot the plunger, which movements are effected by the engagement of pieces of material to be tested on `the platen with the testing;- ball when the'` platen is moved upwardly, and measurement indieating means for showing the results of the tests.

In. the particular embodiment of the invention shown in the drawings, the machine includes a base frame l0, in which'the platen or work support ll and its reciproeating mechanism are mounted, and a pair of vertically extending, spaced screw shafts or rods 12, projecting,` upwardly from the frame and which are adapted to rigidly but adjustably support a yoke 13 which carries the various parts of the measuring,- mechanism in operative position above the platen l1. The yoke 13 is formed with a central hollow portion or cylindrical chamber l5 closed at its upper end by a wall 16.- The measuring unit is releasably secured in this chamber. The measuring unit comprises a cylindrical shell 20, a plunger 21 arranged within the sheil to move axially thereof7 and a strong spring 22 of known or predetermined capacity within the shell, one end of which engages the end wall 23 thereof, and the other end of which is engaged by a follower disk 24 through which the plunger extends, and which bears on an anico nulel" .Shoulder 25 of plunger, so that;A f

upward movements of the plunger act through the follower 24 to compress the spring 22. The spring 22 and follower 2l are retained in the shell 20 by means of a threaded disk 26 which is screwed into the threaded open end of the shell and has a central aperture through which the plunger 2l extends. The upper end oic the plunger passes through the upper end 23 ofthe casing and through an aperture in the top wall 16 of the chamber 15, and is threaded for the reception ot a retaining nut 28 which is adapted to engage the walll6, or an interposed washer, to limit the downward movement of the plunger and prevent it from dropping out ot place. The lower end o't the plunger is formed or provided with means of suitable construction, such as the screw cap 29, for releasably retaining the testing ball or member 30 in place with a portion thereof projecting downwardly towards the platen ll. X

The n'ieasuring mechanismdescribed is entirely self contained, and t'orms a unit which can be readily inserted in or removed from the chamber l5, and when positioned therein, may be held in place by a threaded disk 3l which is adapted to be screwed into the lower end otthe chamber and bears againstthe shell 20. By this construction, the pressure exerted by the spring, when the device is not in operation, is transmitted to the disk 26 through the follower 24 and to the end wall of the shell 2O respectively, s0 that the plunger has no load to support, and a relatively small nut 2S can be used.

An important feature of the measuring element as described is that a plurality ot the shells 2O may be provided, each having a spring 22 ot different capacity therein, for instance, a spring of 3000 kilograms capacity or resistance for testing hard inet-- alsor materials, and a spring of 500 kilograms capacity for testing softer metals or materials. The springs are inserted in the shells at` the 'factory and are adjusted exactly to their intended capacity by turning up the threaded disk 26 to the required degree, and then securing this disk permanently in suchposition as by a set screw 32 extending through the wall ot' the shell and engaging the disk, see Fig. 5. The measuring or resistance unit is therefore complete and its capacity predetermined and known, and one such unit maybe quickly ,substituted oranother without danger ofchanging or requiring' the adjustment of the springs, by lirst removingtheplunger 2l andthe lower disk 31.v After the springshave been once adjusted at, the factory no furthe-r adjustmentis necessary. y 'I j A A further advantage yof the construction shown is'that a relatively7 long spring may be used, thus reducing `the possible degree.`

of error in the indication of the measurements due to the penetration of the test ball in the material, the travel of the platen l1 vbeing always the same, as about'to be explained.

The yoke 13 may be adjustably supported on, lor attached to, the screw rods l2 in any suitable nianner. Yln the construction shown, the threaded portions 33 of the rods pass freely through vertical cylindrical holes 3J: in the opposite ends of the yoke, and a pair of nuts 35, each having threaded engagement with one of the rods l2, bears against the bottom face of the yoke, while a second pairy of nuts 36, threaded on the rods, bear against the top tace of the yoke, and in cooperation with the nuts B'hold the yoke rigidly atv any desired elevation on the rods 12. The nuts are prevented from turning', atter being adjusted, by suitable locking means such as set screws 37 passing through the nuts and bearing against the rods 12. By loosening the set screws 37 and making the appropriate adjustment oit the nuts 3o and 36, the yoke may be raised or lowered to position thev measuring mechanism at any required distance above the platen ll suitable 'tor testing samples varying considerably in thickness. By again tightening the screws 37, the yoke will be held rigidly in its adjusted position.

The work support il is preferably constructed and mounted in the bas@ trame l0 in the 'following manner. The work support comprises a reciprocatory platen carrier 4.0, anda platen member Ll-l movable therewith, and which is adapted to be adjusted axially thereof, and is provided with a platen or anvil 4-2 for supporting the work lV. The carrier l0 is 'formed with a vertical, cylindrical body portion Ll, slidably litt-ing in a bore lll in the upper portion ol' the base l0. and a. horizontal head elfi haring a pin or rod t6 depending therefrom and slidably litting in a guide hole 4S in the base to prevent the carrier 4() from turning during its reciprocatory movements in the bore l/l. rlhe platen member ll is screw threaded and adapted to turn .in a threaded hole 5l in the carrier -lO so that by turning the member ll, as by the hand wheel or disk 52, said member may be adjusted lengthwise so that it can beraised or lowered relatively to the carrier el() tor the purpose et correctly positioning the upper face of the work piece to be tested relatively to the ball 30. y j

The means shown :tor causing the interiittent reciprocation ot the platen 4t2 cludes a horizontal shaft 55 journalled in bearings 56 in the base l0, and having a worm wheel 5i' secured to one end thereof, and meshing with a worm58 for rotating Vthe sha-tt. ,rllhe rworin .58.is secured on .a-

59 adapteduto be driven by any suitshart` able source of power, such as an electric lUl) motor (not shown). The shaft is provided between its ends with a fixed cam or eccentric 60, which during each revolution of the shaft is adapted to lift the platen ll so as to engage the work piece to be tested with the ball 30, force the plunger' 2l upwardly and compress the spring the resistance of whici will cause the ball 30 to indent the work piece.

ln accordance with the present invention a lost motion device is disposed between the eccentric and the lower end of the platen carrier so that noise will be prevented and the parts maintained in Contact should wear between the parts occur. rllhe lost motion device is so constructed that a considerable portion of the lifting action of the rotating cam is expended in taking up the lost motion, the remaining portion only of the upward movement lifting the platen. Thus the platen is held stationary for a considerable portion of each period of each revolution of the shaft, which allows ample time for the insertion, proper positioning, and subsequent removal of the work pieces. The lost motion device shown comprises a saddle or block G2 having an arcuate face 63 adapted to rest on the eccentric 60, and an upwardly extending hollow stem 6st slidably engaging in the smooth lower end of the hole 5l inthe platen carrier 40. The upper face 65 of the block 62 is fiat and is normally held yieldingly a distance below the flat bottom face 66 of the carrier Zl0 as by a coil spring G7 seated in the hollow stem Gel., and bearing at its upper end against a cross pin 68 secured in the carrier l0, whereby the spring also yieldingly presses the block against the cam 60.

Assuming the parts to be in the position shown in Fig. l, then upon the rotation of shaft 55, the cam 60 will lift the block 62 against the action of the spring 67 and will first engage the upper face 65 of said block with the face 66 of the platen carrier, see Fig. G, and the continued rotation of the cam will then cause the elevation of the platen until the high point of the cam is reached, see Fig. 5. The distance that the platen moves upwardly is the difference between the distance between the faces 65 and G6 in Fig. lf and the total throw of the cam 60.

V'l'he provision of the spring G7 permits proper Contact between the cam 60 `and bloclr 62 at all times and thus prevents noise between these parts after wear occ-urs. However, to prevent the wear and consequent variations in; the distance between the faces 65 and 66 from affecting or changing the definite predetermined upward movement of the platen and the extreme upward position of the top face of the anvil or platen 4-2, adjustable takeup means are provided for the purpose of maintaining the proper distance between the faces 65 and 66, and which means also act to limit the downward or return movement of the platen. These means in ne construction shown comprise a stop screw 70 extending downwardly through and having threaded engagement with a hole in the head of the platen carrier so as to Contact with a lined part of the base l0, such for instance as the hardened block 7l. ln practice the screw 70 is adjusted when'the machine is first assembled, so that its lower end contacts with the block 71 just as the faces 65 and 66 are, brought into contact by the movement of the cam 60, and the screw is then vsecured in this position by a lock nut 72, whereby the platen is ensured a predetermined, constant upward and downward movement. As variations due to wear occur between the cam 60 and block 62, the stop screw 70 is adjusted, as may be necessary, to restore the original relation between the faces 65 and 66, whereby the lift of the eccentric is properly transmitted to the platen.

By the construction described, the member lll can be adjusted vertically relatively toA the test ball 30 by means of the wheel or disk 52 to suit the requirements of the particular sample or samples to be tested, and the user will be assured that the exact movement of the platen will occur at each reciprocation. The use ofthe cani for actuating the platen and the yielding lost motion device between these parts provides a relatively simple, strong and practical construction adapted to give continuous and dependable results.

Means of any suitable sort may be used to indicate the measurements of theA indentations made by the ball in the samples to be tested, but preferably a device of the character shown in Figs. l, 2, 7 and 8 is employed and which comprises a standard dial gage 75 for indicating the movement or coinpression of the spring 22, by means of a movable spring projected plunger rod 7 6. rlhe gage 75 is provided with a lug adapted to be inserted between and be rigidly secured to a pair of lugs or parts 77 on the outer .vall of chamber l5,.with the plunger 76 engaging a pin or stud 78 which is rigidly secured to the follower 2l and projects out through registering holes in the shell 2O and the wall of the chamber l5, so that upward movements of said follower, and consequently the compression of the spring 22, are directly indicated. Means are provided in the machine shown for releasably holding the plunger rod 76 in the position to which it is moved by the pin 78, so that the measurement indicator of the gage may be retained in its measurement indicating position as long as desired.. For this purpose a clip 79,

see Figs. 'i' and 8, is provided which is secured to a stationary part ot the gage and has a pair of spring fingers which embrace the rod 76, and while permitting the saine to move upwardly under pressure, will trictionally retain the rod in its raised position until the rod is ieleased and returned by hand to its initial position. The pointer on the dial may be i'eturned to Zero, and the rod 76 lowered by pressing down on the iinger piece 8O on the upper end oi the plunger red. 'E he clip 79 is preferably removably secured to the so that it may be dis sensed with when not desired.

I claim as my invention 1. In a hardness testing machine the combination oi'i a trame, a measuring element having a spring pressed test member supported opposite said frame, a platen movable in and extending from said trame and adapted to be reciprocated toward and troni said measuring element to press a sample against said test member, means torreciprocating said platen, and said platen comprising two members one ot which is movable lengthwise relatively to the other for adjusting the platen to accommodate samples ot di'li'erent thicknesses.

2. In a hardness testing machine the combination of a trame, a. measuring element having a spring pressed test member supported opposite said trame, a platen movable in and extending from said trame and adapted to be reciprocated toward and from said measuring elementto press a sample against said test member, and a driven rotary member `tor causing the reciprocation ot said platen.

8. In a hardness testing machine the combination of a i'rame, a measuring element having a spring pressed test member supported opposite said trame, a platen movable in and extending "from said frame and adapted to be reciprocated toward and from said measuring element to press a sample against said test member, a rotatable shaft and an eccentric on said shaft adapted to move said platen towards said measuring element during each rotation ot said shaft.

4:. In a hardness testing machine the 'combination ot a trame, a measuring element having a spring pressed test member sup ported opposite said trame, a platen movable in and extending from said trame and adapted to be reciprocated toward and from said measuring element to press a sample againstsaid tes-t member, an eccentric, means for rotating said eccentric, and a device disposed between said platen and said eccentric and adapted to be engaged by said eccentric to move said platen during a portion of each revolution of said eccentric.

in a hardness testing machine the combination o' a trame. measuringelement having a spring pressed testmember suppcf-"tec opposite said trainc.y a platen meva 1 in and extending from said traine and amipted to be reciprocated toward and `from said measuring element to press a sample against member, an eccentric, means tor e.. n said eccentric, and a device connected to ,faid platen and yieldingy engaging said eccentric and adapted to be actuated thereby to cause the reciprocation et said platen.

(i, in aliardncss testing machine the combi1A iion oi a iframe, a measuring element having a spring pressed test member supported opposite said trame, a platen movable in and extending trom said Aframe and adapted to be reciprocted toward and from said measuring element to press a sample inst said test member, an eccentric, .ns for rotating said eccentric, and a motion device disposed etween said A n and said eccentric and having a 'tace spa-ced troni a cooperating face on said platen, said device being adapted to be act said eccentric to engage said ta. during a portion ot the littineperiod oit said rotatable eccentric and to litt said aten during the remaining portion ot said period.

i. l'n u hardness testing machine the com- Yon oi a trame. a measuring eiemcnt ia a spring pressed test member suppotcd opposite said frame, a platen mov able in and exteneing from said iframe and adapted to be reciprocated toward and 'from measpring` element to press a. sample against said test member, an eccentric, means for rotating` said eccentric, and a. lost motion device for transmitting motion trom said eccentric to said platen to litt the same, yielding means disposed lietween said platen and said lost motion. device for ),r'ieidingiy pressing said device against said eccentric, and take up means tor compensating for wear between said eccentric and said lost motion device.

8. in a hardne s testing machine the combination oi a frame, a measuring elementl having a spring pressed test member supported opposite said trame, a. platen movable in and extending` from said trame and adapted to be rcciprocated toward and from said measuring; clement to press a sample against said test member. an eccentric, means tor rotating said eccentric, and a device disposed between said platen and said eccentric and adapted to be engaged by said eccentric to move said platen7 said device having a Aface adapted to be spaced a distance Vtrom a tace on said platen when in engagement with the low point on said eccentric.l and said races beine; adapted to be engaged before the high point ot said eccentric engages said def-rice, and the subsequent rotation of said eccentric to the high point causing the platen to be lifted.

towards said n'ieasuring` element during aV portion of each revolution ot said eccentric, and a take-up device tor permitting a delinite litt ot said platen by said eccentric regardless ot wear between said lost motion device and said eccentric.

l0. ln a hardness testing machine the combination ot a frame, a measuring' element having a spring` pressed test member supported opposite said trame, a platen movable in and extending from said trame and adapted to be reciprocated toward and trom said measuring element to press a sample against said test member1 an eccentric7 means yifor rotating aid eccentric, and a lost motion device disposed between said platen and said eccentric and adapted to be actuated by said eccentric to move said platen towards said measuring element during a portion of each revolution ot said eccentric, and an adjustable stop on said platen adapted to engage a fixed part on said base trame and adapted to be adjusted so as to insure a definite litt oi said platen regardless ot wear between said lost motion device and said eccentric.

l1. In ahardness testing machine, the combination of a trame, a measuring element having a spring pressed test member supported above said trame, a platen movable in and extending from said frame and adapted to be moved toward and trom said measuring element to press a san'iple against said test. member, said measuring element having a yielding member adapted to be compressed by the pressure exerted on said test member by said sample, a measuren'ient indicator, a plunger therein adapted to be moved by the compression oi" said yielding member to actuate said indicator, and a. triction member adapted to yieldingly engage said plunger and which acts to permit indicating movements thereof and trictionally holds the same against return movements when the pressure thereagainst has been relieved.

l2. ln a hardnessl testing` machine, the combination of a trame, a measuring element having' a springl pressed test member supported opposite said trame, a work support movable towards and from said measuring element to press a sample against said test member, and means for moving said sam le against said test member before worli support, `said work support comprisingl a platen carrier slidable in a hole in said tra-ine and a platen member `having a work supporting tace, said platen member being adjustable relatively to said vcarrier to positionthe test member engaging t ce ot a said work support is moved.

13. ln a hardness testing machine, Yhe combination o a trame, measuring element having a springl pressed test member pported opposite said frame, aworli support movable towards and from said measuring element to press a sample against said test member, and means for moving said work support, said work support comprising a platen carrier slidable in a hole in said trame and a platen `member having a work supporting tace formed on an end thereof, said platen member having` a screw threaded p rtion engaging in a threaded hole in said platen carrier and adapted to be moved lengthwise thereof to position the test member engaging ifa-ee of a sample against said test member, and a part on said platen member 'for turninCf the same in said alaten carier.

le. in a hardness testing machine, the combination o'l trame, a measuring element having a spring pressed test member supported opposite said trame, a platen movable in and extending from said frame, means 'for moving said platen toward and from said measuring element to press a sample against said test member, said measuring` element having a hollow shell,v a spring arranged therein, a dislr adapted to be securedl in said shell tor holding said spring in said shell and compressing the same to a prede- 'ermined capacity, a stationary yolre having` a cavity therein, said shell, said spring and said disk being' insertible and removable trom said cavity as unit without disturbing the set-ting of said spring, and a plunger tor supporting` said test member in operative relation to said spring.

in a hardness esting machine, the combination oit a trame, a measuring element having a. spring pressed test member supported opposite said trame, a platen movable in and extending Ytrom said trame, means for moving said platen toward and from said measuring A element t-o press a sample against said test member, said measuring element having a hollow shell, spring arranged therein, a disk adapted to be secured in said shell for holding said spring in shell, said dish being adjustable lengtbwise oit' said shell to adjust and compress said spring to a predetermined capacity, a stationary yoke having a cavity therein, said shell, said spring and said dislr being insertable and removable from said cavitj,7 as a unit wit-hout disturbing the setting of said spring, and a plunger for supporting said test member in operative relation to seid spring.

1G. ln a` hardness testing machine, the Combination of :L frame, a measuring element having e springl pressed test member supported opposite said frame, e plnen movable in une extending from said frame, means for movingseid platen towurdend 'from said measuring element to press e snmvseid shell7 zry plunger for -siiid spring in said. shell and holding the same in compression to a predetermined Cepaolty, means for stationarily supporting sunporting said test member so as to compress said spring when engaged by a sample on Said platen, :md said coil spring being` relatively long,

.whereby my error occurringl by .reason of he pene 'ration of said test member into said smnple may be reduced to :i mnnmuin.

DONALD C, DAVS 

